Created attachment 107243 [details]
Changes to nbproject/build-impl.xml

The only two properties that need to be set are

bootstrap.url=
autoupdate.catalog.url=

of course in real life they are supposed to point to some HTTP resource, not to a local mirror (possible due to impl of bug 196428) like in the patch. The properties should be populated by the apisupport.project UI.

core-main #4b4f2072f2fc does the Ant part. GUI integration may be trickier.

Integrated into 'main-golden'
Changeset: http://hg.netbeans.org/main-golden/rev/4b4f2072f2fc
User: Jesse Glick <jglick@netbeans.org>
Log: Ant portion of #197038: download platform on demand.

Works if you set up the right properties as listed in README. What is not available:

1. A wizard to set up downloadability to begin with. Can use nbms-and-javadoc for tasks.jar; ought to inspect the version of the current platform, and offer a "well-known" URL from updates.netbeans.org.

(See e.g. PlatformChooserVisualPanel.cleanupLabel and NbPlatform.getDefaultJavadocRoots for approaches, though in the future it would be better to have a general API for finding a logical version of both harness and platform that did not need to be hardcoded in apisupport.ant; cf. bug #200520.)

Would then remove nbplatform.active, pick a relative location for the download (e.g. ${basedir}/nb/), and set the various properties needed. TBD if any support for undoing all this is needed as well. Possible UI would be a checkbox "Download Platform" in SuiteCustomizerLibraries, though it is also legal to have a relative platform location without using automatic downloads.

2. FixInfo integration to permit a missing dependency to be resolved by download.

Integrated into 'main-golden'
Changeset: http://hg.netbeans.org/main-golden/rev/edade4601765
User: Jesse Glick <jglick@netbeans.org>
Log: Best practices for downloaded platforms (#197038) is to skip defining nbplatform.active, which harness supports so evaluators should too.

I am testing this functionality so that I can write a Test Specification for it. I created a Standalone Platform Application.

The details of my environment are:
Product Version: NetBeans IDE Dev (Build 201111070600)
Java: 1.6.0_26; Java HotSpot(TM) 64-Bit Server VM 20.1-b02-383
System: Mac OS X version 10.7.2 running on x86_64; MacRoman; en_US (nb)
User directory: /Users/tusharjoshi/.netbeans/dev
Cache directory: /Users/tusharjoshi/.netbeans/dev/var/cache

The properties I wrote in platform.properties are :

nbplatform.downloaded.label=Downloaded Platform
nbplatform.downloaded.netbeans.dest.dir=${suite.dir}/nbdest
bootstrap.url=http://deadlock.netbeans.org/hudson/job/nbms-and-javadoc/lastStableBuild/artifact/nbbuild/netbeans/harness/tasks.jar
autoupdate.catalog.url=http://deadlock.netbeans.org/hudson/job/nbms-and-javadoc/lastStableBuild/artifact/nbbuild/nbms/updates.xml.gz 

The error I am getting is as follows:
platform.download:
Downloading clusters platform
Getting: http://deadlock.netbeans.org/hudson/job/nbms-and-javadoc/lastStableBuild/artifact/nbbuild/netbeans/harness/tasks.jar
To: /var/folders/c3/z3fsf3pd44xdzcm8nxftszk40000gn/T/tasks.jar
local file date : Tue Nov 08 06:54:11 IST 2011
Not modified - so not downloaded
Downloading http://deadlock.netbeans.org/hudson/job/nbms-and-javadoc/lastStableBuild/artifact/nbbuild/nbms/updates.xml.gz
/Users/tusharjoshi/NetBeansProjects/suite2/build.xml:7: The following error occurred while executing this line:
/Users/tusharjoshi/NetBeansProjects/suite2/nbproject/build-impl.xml:41: The following error occurred while executing this line:
/Users/tusharjoshi/NetBeansProjects/suite2/nbproject/platform.xml:29: installdir must be existing directory: /Users/tusharjoshi/NetBeansProjects/suite2/${nbplatform.${nbplatform.active}.netbeans.dest.dir}

What property is missed by me?

Using the following properties in the platform.properties file this feature worked.  

suite.dir=${basedir}
nbplatform.active.dir=${suite.dir}/nb
harness.dir=${nbplatform.active.dir}/harness
bootstrap.url=http://deadlock.netbeans.org/hudson/job/nbms-and-javadoc/lastStableBuild/artifact/nbbuild/netbeans/harness/tasks.jar
autoupdate.catalog.url=http://updates.netbeans.org/netbeans/updates/7.0.1/uc/final/distribution/catalog.xml.gz

I have verified this on the following environment:

Product Version: NetBeans IDE Dev (Build 201111070600)
Java: 1.6.0_26; Java HotSpot(TM) 64-Bit Server VM 20.1-b02-383
System: Mac OS X version 10.7.2 running on x86_64; MacRoman; en_US (nb)
User directory: /Users/tusharjoshi/.netbeans/dev
Cache directory: /Users/tusharjoshi/.netbeans/dev/var/cache

Setting back the issue to RESOLVED-FIXED status as it was earlier.

Verified only for the manual update to the platform properties file.
This issue shall still be kept open for the GUI Part.